1. Field of the Invention
This invention relates to heat exchangers and, more particularly, to structure for sealingly mounting modular cooling cores on a radiator frame.
2. Background Art
It is known to construct heat exchangers, such as radiators used with internal combustion engines, with modular cooling cores communicating between inlet and outlet manifold tanks. The modular construction is preferred to a single piece core construction particularly in high stress environments, because it is more durable than a radiator with a one piece core, and in environments where physical damage to the core section is likely.
The principal advantage with the modular construction is that one need only remove and replace or repair the damaged core module, leaving the remaining modules in place. The individual core modules can be easily removed and replaced at a relatively modest cost, whereas damage to a portion of a single piece core may require removal and replacement of the entire core section. This is time consuming and costly.
In the event that a core module is damaged and a replacement is not readily available, the ports in the defective core module can be plugged, with the module reinstalled, to continue operation of the engine at partial load (depending on ambient temperature) until a replacement can be procured.
A further advantage of the modular construction is that the core modules have some inherent flexibility on the radiator frame and will absorb shock and accommodate twisting and thermal expansion better than a single piece core is capable of doing.
Some conventional core sections have upper and lower collecting tanks connecting to the inlet manifold tank and outlet manifold tank, respectively, through projecting tubes which are sealingly accepted in ports in the manifold tanks. Heretofore, relatively complicated structures have been used to mount the core modules on the radiator frame.
One example of a prior art structure is shown and described in U.S. Pat. No. 1,354,341, to Rossi. In Rossi, core modules are provided with upper and lower rearwardly projecting nipples which are extended through ports in spaced manifold tanks. With the nipples and ports aligned, each module is pressed towards the tanks to compress the nipples sealingly in the ports. A strap and bolt are used at both the upper region and lower region of each core module to prevent the nipples from escaping from their respective tank ports.
It is also known to have inlet and outlet tubes on core modules that are in axial alignment with each other, such as those shown in U.S. Pat. No. 4,236,577, to Nendeck. In Nendeck, each module has an elongate cylindrical configuration with reduced diameter ends for reception in axially aligned ports on spaced manifold tanks associated with a frame. One of the reduced diameter ends is sufficiently long that it can be directed vertically through one port in the frame, with the module slightly tilted, far enough to allow the core module to be reoriented to align the lower end over the other port. The module is shifted axially to seal its other end. A substantial amount of space is required over the top frame port to permit the required penetration by the one module end. Further, a substantial length of the core has the reduced diameter to permit passage through the one port, and this may undesirably limit flow volume and heat exchange surface area.
As an alternative to assembling core modules with axially aligned inlet and outlet tubes according to Nendeck, the inlet manifold tank can be built around the core modules that are already in place on the outlet manifold tank. This, however, complicates assembly and disassembly of the core modules. Some of the benefits of the modular core construction would therefore not be realized.